Improved extensioh-ladder



@uitrit tat-rs atrnt @Affina Letters Patent No. 80,367, dated July 28, 1868.

IMPROVED XiTENSION-LADDER.

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TO ALL WHOMv IT MAY CONCERN:

Be it known that I, JOHN A. SMITH, of Lacon, in the county of Marshall, and State of Illinois, have invented a new and useful Improvement in Extension-Ladder; and I do hereby declare that the following is a` full,'clear, and enact description thereof, which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

The gure is perspective view of .my improved ladder extended. I

"My invention has for its object to furnish an improved extension-ladder, designed especially for firemen, painters and tinners use, but which shallfhe equally applicable for other uses, which shall be simple in construction, easily adjusted, extended, and moved from place to place; and it consists in the construction, combination, and arrangement of the various parts, as hereinafter more fully described.

My improved extension-ladder is made in twoor more sections, each upper section fitting to and between i the sidehars of the next lower section.

A is the lower section, the side-bars a of which may be made pointed to prevent4 them from slipping when the ladder is being used. The cross-bars a2, which form the rounds or steps of the ladder, are securely attached to that side of the side-barsa1L which will be outward when the ladder is raised. i

The cross-bars b2, oi` the section B, are attached to the sidelbars b1 of said section, said side-bars b being made enough narrower. than the side-bars n" to allow the cross-bars b2 to slide down within the cross-hars a2 when the ladder is closed. Y

The thirdsection C is made in thc same manner to work in the section B. To the upper ends of the sidehars C1, of the upper section C, are pivoted wheels D, to diminish the friction when raising the ladder along the walls'of buildings, and also to enable the ladder when closed to be moved from place to place, in the manner of a barrow. i i

Upon the inner side of the side-hars of-each outer section.I and upon the outer side of the side-bars of each inner section, are formedlongitudinal grooves, the grooves of each pair beingplaced directly opposite each other, and having stop-pins or blocks in their ends to guide the sections in their upward and downward movements, and to prevent each inner section from being entirely withdrawn from its adjacent outer section.

E are stop-bolts, which pass in through the side-bars al of the outer section A, and are forced inward, and held in place by spiral or other springs attached to them, and placed in recesses formed in the said side-hars (t1, said recesses being covered by pla-tese attached tothe outer sides of the bars al, as shown. The heads of the Vbolts E are made in the form shown in the figure, so that when the bolts are turned in one direction, the bolts may he drawn or forced inward by the action of the springs attached to them, andso that when drawn outward, and turned oneq'uarter around, the shoulders of' the bolt-heads may rest against the plates c' and hold the bolts away from the side-bars l oi' the inner section B.

In vthe. outer side of the side-bars boiV the inner section B are formed holes, to receive the end oi' the v` bolts E to support the said section at any desired point. The lower sides of cach oi' these holes, except the upper one, is bevelled out so that the section B, when fully lowered, may be securely locked by the bolts E, 'and in all other positions be held securely from descent, while at the same time it may be raised-freely.

F are bolts, constructed and operating exactly like the bolts E, which pass in through the side-bars c of the section C, and enter holes in the inner sides ofthe side-bars b' ofthe section B, exactly similar` to the holes in the outer sides ofl said bars, except that the upper sides of all the holes, except the lower one, are bevelled, asshown in the drawing.` l

are jointed braces, the upper ends ofthe upper parts gl of which are pivoted to the upper parts of the side-bars bl of the central section B. The upper ends of the lower parts g2 are pivoted to the lower ends of vthe parts g1, and are held in theirproper relative positions, with respect to eachother, b'yv thefcouneeting-rtl g3. When required for use,the lower endsot the parts g2 are inserted in one or the other of a series of holes formed in the edge of the side-bars b1, so that the brace G may project more or less according to the position of the ladder. When not in use, the brace G is extended along the section B, and secured in place by hooks or keepers attached to the edges of the side-bars bl. The braces G, when the ladder is fully extended, rest' against the Wall of the building, and support and strengthen themiddle part of the ladder.

i H are guide and stay-ropes, which are attached to the upper part of the side-bars of the upper section C of the ladder, to guide it while being raised and lowered, to stay or brace it when raised, and to withdraw the upper end of the ladder from the wall for the purpose of using vthe said ladder to break or dash in a window Y. when necessary. Y

I is a shaft, working in bearings attached to the lower part of the. side-bars Va, and which is operated by a crank, J, attached to one of its projecting ends. l

- =K .is a rope, one end of which is attached to the crank-shaft I. 'Ihe rope K passesover a pulley, L, pivoted to the cross-bar a3, attached to the upper ends ofthe sidefbars'al, and has a hook, k,.at tached to its other or free end, so that the sections B and C may be raised by hookingthe hook k into an eye attached to the centre of the lower cross-bar of said sections.

The shaft I is held iu anyposition to 'which it may be revolved by the pawl M, pivoted to the Aside ofone of the side-bars al, which takes hold of the teeth of the ratchet-wheel N attached to said'shaft I.

In 'using ladder, it is raised, when closed, against the wall of the building, and the hook c is rthen oonnected with the section to he raised. The spring-bolts that lock the .section to be raised are then drawn out and turned one-quarter around. A half turn is then given to the crank J, and the spring-bolts turned back'an'd allowed to spring into their places. 'lhe section isA then extended-to any desired extent by operating the crank, J. The other section or sections may then be extended in the same manner.

I claim as new, and desire to secure by Letters Patent- The extension-ladder, constructed, as described, of the three sections A B C, sliding in grooves, one within the other, and provided with'the adjusting-screws E F, and the adjustable braces G, composed of the rods g1 g2 g3, all arranged as describcdfor the purpose specied.

. JOHN A, SMITH.

Witnesses:

A. MeKEoN, JAMES H. THOMAS. 

